Xx x s x s



W. H. BROWN.

DIFFERENTIAL MECHANISM.

APPLICATION FILED JULY 16. 1917.

1,308,520. Patented July 1, 1919.

29 70 77 17 I 72 g 6, 7/ as A 715 Jim W (.0 WASHINGTON, D. t:v

rr'nsrnrnnr ornro WILLIAM H. nnown, or onicneo, ILLINOIS.

DIFFERENTIAL MECHANISM.

soaseo.

Application filed .TuIy 1c, 1917 Serial No. 180,733.

To all whom it mag concern:

Be it known that 1, WILLIAM H. Bnown, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful-Improven' ents in Differential Mechanism, of v which the following is a specification.

This invention relates to a differential mechanism, and more particularly to a differential mechanism of that character ordinarily employed in the construction of motor Vehicles and the like, its function being to effect the transmission of power from a single drive shaft, driven by the motor, to separate driven shafts, upon which are mounted the drive wheels, and at the same time permit one or the other of thewheels to rotate at a greater speedwhen the vehicle is moving in a curvilinear path.

As appliedto motor. vehicles, a differential mechanism is ordinarily located in and forms a part of thereary axle of the vehicle and comprisesan arrangement of .rotative members intermediate the drive shaft and the separate driven shafts, and so constructed asto operate automatically to permit the increased speed of the outside wheel (that is, the wheel which describes the arc of greater radius) without interrupting the transmission of power to at least one of the driving The purpose of this invention is to provide anovel construction for a differential mechanism, departing from the usual arrangement employed, whereby certain advantageous results are obtained, which will.

be hereinafter clearly pointed out.

The novel features embodying the invention are illustrated in the accompanying drawings, wherein- Figure 1 is a view in longitudinal section f of the differential mechanism and associated parts;

Fig. 2 is a cross-sectional view taken on line 22 of Fig. 1; I

Fig. 3 is an enlargedfragmentary View of the members of the device, showing the shifting mechanism; and i Fig. 1 is a cross-sectional view taken on 1 line 4-4 of Fig.1.

The differential mechanism and parts connected therewith "comprise, in "general, a drive shaft 10, which extends rearwardly from the motor at right-angles to the rear axle; two separate driven shafts 11, 11, in-

closed within the rear aXle housing consist Specification of Letters Patent.

Patented July 1., 1 919.

ing of tubular members 12, 12,which form, together with an enlarged housing 13 the Refer "ing more in detail to the differential InGClliLlllSlTl, the same comprlses, as its mam element, a cylindrlc shaped caslng or drum 14, adapted to rotate about an axis coinciding with the axes of the drivenshafts 11, 11,

and for this purpose providedat opposite ends with tubular bearing sleeves 15, 15, which surround the driven shafts and proj ect into annular spaces, in which are mounted antifriction rollerbearings 16, 16, the latter being surrounded by tubular extensions 17, 17 at the ends of the differential housing 13. The drum or casing 14 preferably consists of two parts or halves, bolted together at the centerof the drum by the provision of marginal'flanges 18 and bolts 19. Rigidly fixed to the drum and surrounding the central portion thereof is a beveled gear wheel 20, which is fastened by means of said bolts 19, which securely connect the same to the flanges 18, 18. The gear wheel 20 rotates with the drum 14- and meshes with a beveled pinion 21 mounted on the end of the drive shaft 10, which extends into the differential housing and is supported at the point of entrance by a roller bearing construction 22.

Within the drum or casing 14 is formed an elongated, cylindrical shaped chamber, which contains other members ofthe mechanism, arranged as follows: Upon the inner ends of the driven shafts 11,11, which extend into said drum and terminate in close proximity and at the center thereof, are mounted hub-1nembers 23, 23,.said l1ub-membersbeing rotative with the driven shafts and preferably connected thereto, by the V provision of axial boresfrectangular-in contour, which engage squared endportlons of theshafts 11, 11. Each of these hub-members occupies substantially one-half the lengthof the space within the drum 14., al-

though a space is provided between them,

for a purpose hereinafter set forth. Each of these hub-members is provided at opposite ends with flanges 2a, 25, the opposed faces of said flanges being provided with radial ratchet teeth 26 and 27, respectively. The ratchet teeth are cut or formed in opposed relation, that is, the. contact faces of the teeth 26 face in one direction, whereas the. contact faces of the teeth .27 face in the opposite direction. .,Between the flangesv 2i 2(ipanda27, respectively, of the hub-members. Arranged about rthe periphery of each ring are lugs 31 pro ect1ng outwardly and engag ng a aseries of ,grooves 32, .32,

formed upon ,the inner. surface of the drum and extending longitudinally thereof,,each

series off grooves .32, .32nexten ding .from the centralportion of the, drum outwardlytowardthe endshthereof. 9 By the arrangement thus employed, the shift rings 28,. 28 rotate with the drum and; at the same time .are capable of. endwise movement, uponthe central bearingportion of. the hub-members and 1nto and out of locking connection withathe 'end flanges .of the hubmembers,

through; the medium. of the ratchet teeth. The :fianges 24 2541 are rigidly connected withi-the. hub members 23 so as to rotate therewith, but Tthe connection; of each flange 25 .is' such that the latter may be. placed on the hub member 23 after the associated shift ring, 28 ;has beenapplied thereto,

n .As shown ;i,l1 .the drawings, the lefthand shift ring engages the ratchetteeth 27 of ithe inner. flange 25.;ofr its associated hub- .niember, whereas-the right-hand ing engagesathe. teeth 2630f the outer flange,2l of its associated hujb -men'1ber, this being the preferable; arrangement of the ringsifor driving the vehicle in a forward direction, as indicated by the arrowsinFig. 1. Thus, when the rings are'shifted to the right-hand end of theirhub-members and into locking engagement therewith, the drum 14 is positively connected. to the. hub-members and driven shafts, so that power is transmitted positively to the latter, his to be noted in this connection that the ratchet teeth at theright-hand end of each hub-member are identical in arrangement, whereas the lefthand sets of ratchet teeth are, similar to each other in arrangement, but reversed withrespect to the opposed sets of teetln ,Now, if the direction of rotation of the drum were reversed, it is evident that the .sets of ratchet teeth would become disengaged and the rings shifted toward the of each rod provided an,enlargedhub 35 ,having a helical thread. extending fronnleft to. ,right throughout its length. l v .Mounte d but this frictional engagement is not,

ing pins or rods 33, preferably three in number, arranged at angles of120 apart, as shown in Figs. 2 and 4;, and ilncoiicelitric relation about the co nmoir axis of the rotative parts, said rods extending; through openings formed in said rings and a short distance beyond,. the portioinof the rings surroundingthe openings being preferably reduced in, thickness by the provision of eircular 'depressions 34 formed ,on opposite sides of each ring... At the central portion upon each huh [35,is a sn'iallfpini'on 3'6 haring threadedengagement witlrthe hub, and

capable of producingrelative en'dwise move- .ment between the ,san e and the rod, when. .thelatter is rotated. Eaclr'pinion ispref- .erably provided with end, flanges 36", which extend outwardly beyond the teeth, fl he purpose of these fianges, will be hereinafter set forth. Mountedbetween the hub-incur bers 23, 23 isa circular jplate 37, Qf,Si1l)- stantially the same. diameter asthe flanges of said hub-members; and proyided with pe .rlpheral gearteeth. vThis plate meshes ,with

the several pinions, which are so arranged as to retaln orsupport the plate at threc {points l he plate is disconnectedfrom the hub-members, but. the latter. preferably haige SLIffiC1G11i bear ng or fr-lct onal engagement against opposite sides of the plateto effect the rotation of the plate with tlielnihane nbers,undennormal operation of the device, so great as to prevent the, relative rotation between the'parts as is occasioned when one of the hub neinbers rotated t n1; or less speed than the other. Mounted upon each rod 33, andon opposite sides (semen ring, are pairs of springs 38. and,39, the inner pair; 39 extending between the central hub 35 and each r1ng,,and the enter pair from the rings to; the, ends. of eaql i rod,

there being providednlltsrf Q at siaid. ends to retain the springs in position. The springs arepreferably of equal size and length in .order that they may exert thesame degree of tension, thus producing a balanced condition between the spr ngs, as will be hereinafter understood. The function ofthe rods 33 and parts thereof is confined to theshifting of the rings when the direction of the iio vehicle-is reversed from forwardtc baclc ward, and hence when the direction of rota tion of the druml l andshiftrings 28, 28 1s reversed. During theintervaluthe reversal is taking place, the power transnntted is practically zero,hsince a vehicle is ordinarily brought to rest: in reversing hence it is to be understood that the rings are capable of being shifted withrbut little effort, and further that the hub-members would ordinarily be rotating at the same speed and carrying with them :the plate 37. i

The operation of thelshifting mechanism will be iuiderstoodi from the following ris suming that the parts are in the position shownin Figs. 1 and 3, and the vehicle is being driven in theuforward direction, the drivingshaft is positively connected-to both driven shafts through the engagement of the ratchet teeth of theshift rings andhubmembers, and all parts rotate together at the right-hand hub-member and shift ring,

the latter being shifted to the left a distance to permit the disengagement ofthe teeth and the increased speed of rotation of the hub-member, which is accompanied by the passing of the teeth over each otherguntil uniform speed is resumed, whereupon the teeth ar ainqbecomeengaged and the power is transmlttcd to the right-hand wheel as before. During this shlftingjiof the ring out of engagement, there is a slight lend- 40,

wise movement to the left, whichjisopposcd by the springs 39 on the rods 33, the rods, however,remaining undisturbed. The same springs 39galsoact to, force the rings into engagement wlth the hub members when drivmrr connection 131 resumed. The same is true of the left-hand members when the vehicle makes a turntothe right. a

Now, if it is desired to reverse thevehicle to travel ina backward direction, the drum will be rotated in the opposite direction,

of the arrangement ofthe ratchetteeth, both shift rings will obviously be disconnected from the hub-members and shift endwise toward a position between the two, sets of At the instant disconnection takes place, i

there isa relative rotation between the rings and the hub-members, the latter including the plate 37; in other words, the rings will rotate about the hub-members and so will the pinions 36 rotate about the plate 37. This rotation imparts a rotative movement to the pinions, producing a relative endwise movement between the same and the rods 33,

by reason oftheirthreaded connection with the hub-portions thereof. The pinions are restrained from endwise movement by the endflanges 36 36 which engage the plate 37, thus the rotative movement of the pinions effects the endwise movement of the rods in a direction not onlyto relieve the tension exerted by the springs, but to shift the rings toward the left and into engagement wlth the opposite set of ratchet teeth, thus restoring the connection between the drum and driven shafts for driving the vehicle in the, opposite direction.

When the vehicle is again reversed, the shifting mechanism operates in the same manner to shift the rings in the opposite direction, it being manifest that the purpose of this mechanism is to aid in the shiftlng of the rings when reversal takes place, thus insuring the shifting of therings to secure a positive disengagement and engagement of the sets of ratchet teeth. f

The members of the device constitute an intermediate driven member, embracing parts havin positive connection with the driving shatland with each driven shaft,

said parts having ratchet-toothed connectlon, which is automatically and temporarily released by the increased speed of either of the driven shafts. Furthermore, provision ismade for reversmg the directlon of the vehicle, by the provision of sets of oppositely disposed teeth, which operate only when the vehicle is driven in the opposite direction, and, furthermore, means for insuring the shifting of the ringsto bring about the immediate and positive engagement of the proper sets of ratchet teeth.

The novel features of the invention are more specifically pointed out in theappend ed claims. t v,

I claim as my inventienz v ,1.In a differential mechanlsm, the comjbinationof a drive shaft, separate driven shafts, an mtermed ate drlven member, com

prising shiftable members; provided with ratchet teeth, said shiftable members being rotatively mounted on said driven shafts between sets of ratchet teeth on said driven carrying the shift rings with it. By reason shafts, and means including a member engagingsaid driven shafts between said shiftable-.members; for effecting the shifting of prising shiftable members provided with ratchet teeth, said shiftable members being rotatively mounted on said driven shafts between sets of ratchetteeth on said driven shafts, and means including a member inter'pos'e'd between the opposed "ends of said drive'n shafts and having engagement therewith for effecting the shifting of said shift-.

able members into and out 'of engagement with the s'ets'of teeth 'on said driven shafts upon the relative rotation of said driven shafts an'dsaid shiftable members.

In differential mechanism, the combination of a drive shaft, separate driven shafts, an intermediate driven rnember, comprising shiftable members provided with ratchet teeth, said shiftable members being 'rotatively'mounted onsaid driven shafts between sets of 'rat'dhet teeth "on said driven shafts, a circular splate interposed between the opposed ends of said driven shafts'and having frictionalengagementtherewith, and means connecting said shiftable) members together and having operative -connection with said" late for'e'ffecting the shifting of said shi'fta l'e members into and out of en gagement with thesets-of ratchet teeth on said driven shafts upon the relative rotation of said driven shafts and said-shiftable 1 members.

*4. In adifferential mechanism, the combination "of a 'dr'i've shaft, separate 'driven shafts, an intermediate driven member, comprising shiftablemembe'rs provided with ratehet teeth, said *shiftable "i'i'iGli'lbGIS being rotatively mounted o-n-"said driven shafts bemounted on said rod and having power transmitting connectlon with'said plate, and

means connecting said rotativeineniber with "said rod whereby the latter "may be moved endwise upon the rotation of said'plate relative to said shiftable' members.

In a 'difierential mechanism, the com brnation of a drive shaft, separate driven shafts; intermediate drivenjiiiember', eomprising 1 shiftable members in positive drivp ng connection with said drlve shaft and retatively; mounted 'on' said driven shafts,

separate means for Connecting said sh'iftable 'cdfliestizth'is 1mm my hs ot'tinea for five 'cents weary-addressin the commissioner of Patents,

members and driven members when the shiftable members are rotated in opposite directions, and means, operated by the relative rotation of said driven shafts and shiftable members, for shifting the latter, comprising a rod connecting said shiftable members, a gear member rotative with said driven shafts, a pinion mounted on said rod and meshing with said gear member and arranged on said rod to impart endWiSe movement thereto when the same is rotated.

6. In a differential mechanism, the combination of a drive shaft, separate driven shafts, an intermediate driven member, comprising a rotative drum in driving connection with said drive shaft, shift rings rotative with said drum and mounted on said driven shafts, said driven shafts and rings being provided with sets of complementary ratchet teeth, and means for shifting said shift rings, comprising a rod yieldingly connecting said rings, a pinion mounted on said rod in threaded engagement therewith, and a gear member rotative'with said driven shafts andmeshing with said pinion.

7. In a differential mechanism, the combination of a drive shaft, separate driven shafts,an intermediate driven member embracing a rotative drum in driving connection with said drive shaft, shift rings rotative with said drum and mounted on said driven shafts, said rings and shafts being provided with complementary sets of ratchet teeth acting to connect and disconnect the same, a rod yieldingly connecting said shift rings, a pmion mounted on said rod and engaging a threaded portion thereof, and a gear memberrotative with said driven shafts and engaging-said pinion, the latter being rotated in the relative rotation of said shift rings and driven shafts, to impart endwise movement to said rod.

.111 testimony'that I claim'the foregoing as my 111vent1on,I aiiixmy slgnature in'the presence of twowitnesses, this 9th day of -washin am; n. e." 

